98 Chevy k3500. My left blinks real fast while right
side blinks real slow. Where can I be losing ground
There should be a wire on each side front and back that run off of the tail light sockets to the body. Same in the front. Just have to look for and trace the black wire. Blinking fast also is an indication of a burnt out bulb on that side so check the bulbs also, or try a new flasher.
I forgot to put in, my cabs lights also blink with right side
Check all the ground wires you can find, clean them, make sure there are none broken.